JPS60255933A - Device for cooling metallic strip - Google Patents

Abstract

PURPOSE:To cool uniformly a metallic strip without causing any deformation, etc. by transporting the metallic strip along the peripheral surface of the drum part of a cooling roll, and bringing another roll which is provided opposite to the cooling roll into contact with the rear surface of the metallic strip. CONSTITUTION:A steel strip W is transported along the peripheral surface of the drum part of a cooling roll 1, and cooled by passing a refrigerant such as water through the refrigerant flow passage 1.1 of the cooling roll 1. In said device for cooling metallic strips, one or more other cooling roll 2 which contacts with the rear surface side of the steel strip W is provided opposite to said cooling roll 1, and a refrigerant is passed through the refrigerant flow passage 2.1 of the roll 2 to cool the rear surface side of the steel strip W. Consequently, the whole surface of the steel strip W is uniformly cooled regardless of unevenness of the steel strip W and without promoting the deformation of the steel strip W at the parts C and C' of contact between the peripheral surface of respective cooling rolls 1 and 2 and both surfaces of the steel strip W.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device suitable for cooling a metal strip running in a line, such as a copper strip in a continuous annealing process or a continuous hot-dip plating process.

BACKGROUND ART As a cooling method for steel strips in continuous annealing treatment and continuous hot-dip plating lines that include heating and cooling steps, a method using a cooling roll has been implemented. As shown in Fig. 5, a cooling roll (1) having an internal water-cooling structure is disposed in a continuous annealing treatment line, and the circumference of its body is In this method, a heated copper strip is wound around the surfaces (1 and 2) and moved while cooling the wire strip by heat conduction between the circumferential surface of the body of the roll and the copper strip. In this case, if the temperature of the copper strip is rapidly cooled from, for example, 650°C to 400°C with one roll, distortion of the copper strip and other problems will occur, so normally a cooling roll is used as shown in the figure. (1) are arranged in series, the temperature drop width of the copper strip in each roll of each stage is set to an appropriate value (for example, 40 to 50 degrees Celsius), and the prescribed cooling rate is achieved by passing through all the rolls. The processing conditions are controlled so that the temperature is cooled to the target temperature.

However, with conventional cooling rolls, it is extremely difficult to uniformly cool the entire surface of the steel strip, resulting in deformation of the copper strip and uneven material quality due to uneven tension distribution in the width direction and longitudinal direction. easy.

This is because the shape of the steel strip introduced into the cooling roll section is not completely flat in both the strip width direction and the longitudinal direction.
This is due to the slight wavy unevenness caused by so-called edge elongation and mid-elongation that occur during the original plate stage and heating process. That is, at the contact portion (C) between the cooling roll and the adjustment belt, the adjustment belt (W) is in contact with the cooling roll (1) as shown in FIG.
) The part (a) that is curved convexly with respect to the circumferential surface of the roll contacts the circumferential surface of the roll, and the part (b) that is curved concavely with respect to the circumferential surface of the roll forms a gap (S). Sign. Although the figure shows the board width direction, the same applies to the longitudinal direction.

The contact portion (a) is rapidly cooled, and the non-contact portion (b) receives the heat insulating effect of the air layer in the gap (S), so that the cooling rate is extremely slow. As a result, the tension distribution in the copper strip becomes uneven, causing contraction in the strongly cooled contact area (a).
The copper strip (W) is sent to the next cooling roll in a state where its unevenness is more intense than before it comes into contact with the cooling roll (1). In the cooling roll portion of the next stage, the unevenness is further strengthened by the speed and speed of cooling of the contact portion (a) and non-contact portion (b) in the same manner as described above. Due to repeated uneven cooling, the shape of the copper strip becomes noticeably deformed, and
As a result of the difference in cooling effect between the contact area and the non-contact area with the cooling roll circumferential surface, the material of the obtained steel strip lacks uniformity in the width direction and longitudinal direction.

The cooling device of the present invention has been made to solve the above problem, and is characterized by a cooling roll that abuts the back side of the metal band with respect to the cooling roll around which the metal band is wound. One or more metal strips are provided to cool the metal strip from both sides.

The present invention will be explained with reference to the drawings. In Fig. 1, (2) shows a copper strip (W) facing the cooling roll (1).
This is a cooling roll arranged so as to come into contact with the back side of the The cooling roll (1) around which the copper strip (W) is wound has an internal cooling structure, and the outer circumferential surface of the roll is heated to a predetermined level by a refrigerant such as water passed through the internal refrigerant flow path (l・1). The point of cooling and maintaining the temperature is not particularly different from that of conventional cooling rolls. Further, the cooling roll (2) disposed opposite to the cooling roll (1) also has a similar internal refrigerant flow path (2/1).
It may have the following. However, the diameter of the roll body of the cooling roll (2) does not necessarily have to be any size (it may be relatively small).

Note that the cooling roll (1) and the cooling roll (
In 2), the cooling conditions such as the temperature of the circumferential surface of the pass roll are set so as to have the same cooling effect on the copper strip.

According to the present invention, the copper strip (W) is cooled from both sides by the cooling roll (1) and the cooling roll (2) while being continuously transported. Looking at the contact areas (C, C') between the cooling rolls (1, 2) and the copper strip (W), as shown in Figure 2, there is a convex portion on the cooling roll (1) around which the copper strip is wound. (a) is cooled by contacting its cooling roll (1), while its recess (
h) becomes a convex portion with respect to the other cooling roll (2) and is cooled by contacting that cooling roll (2). Zunawara,
The copper strip (W) is cooled in the same strip (1) by contacting one of the cooling rolls on each uneven portion.
ζ Unlike the conventional method, deformation is not promoted, and a cooling effect is produced almost uniformly over the entire surface of the steel strip.

If the difference between the temperature of the copper strip to be cooled and the surface temperature of the cooling roll (2) is large, as shown in Figure 3, multiple cooling rolls (21, 22, 23...) are What is necessary is just to make it oppose a cooling roll (1), and to install it.

In the device of the present invention, each uneven portion (a, b) of the steel strip (W)
are cooled by contact with the cooling rolls (1, 2), and contraction stress is generated equally in each unevenness. As a result, the steel strip (W>) tends to become flatter than the initial state. (If a suitable rolling blade is added to the copper strip (W) at (1, 2), flattening will be promoted and the cooling process will be made more uniform.

FIG. 4 shows an example of a general continuous annealing facility to which the cooling device of the present invention is applied. The copper strip (W) is unwound from a payoff reel (30), passed through a surface purification treatment device (31), and introduced into a continuous annealing furnace.
), the temperature is maintained at the specified temperature, and then the -th cooling zone (3
4), and then cooled relatively slowly in the secondary cooling zone (3).
In step 5), the material is cooled to the target temperature at a predetermined cooling rate by the cooling device of the present invention having an appropriate number of cooling rolls (1) and cooling rolls (2) attached to each stage of the rolls.

Then, after being subjected to a predetermined heat treatment in an overaging treatment zone (37), it is cooled in a final cooling zone (38) and wound onto a take-up reel (39). It goes without saying that the cooling device of the present invention may also be used in the final cooling zone (38).

As an example of continuous annealing treatment using the above continuous annealing equipment,
A cold-rolled steel strip (width 1240-1A, thickness 1-.0-mm) was transferred at a line speed of 160 m/min, and heated to a heating zone (32).
After heating and soaking to 75 (1℃) in the soaking zone (33), -
It was cooled to 650°C in a secondary cooling zone (34), and then cooled to 400°C at a cooling rate of 100°C/sec in a secondary cooling zone (35). However, the cooling roll (1) around which the copper strip of the cooling zone (35) is wound has five stages, and the temperature of the outer peripheral surface of the body is maintained at approximately 200 to 250°C by internal water cooling. Further, each cooling roll (1) is provided with two cooling rolls (2) opposite to it at each stage, and the temperature of the circumferential surface of each body is kept cooled at 150 to 200°C. After passing through the cooling zone (35), the overaging treatment zone (
An overaging treatment of 400° C. x 150 seconds was achieved in 37), and the final cooling zone (38) was cooled to 130° C. by blast cooling at a cooling rate of 5° C./second. The shape of the copper strip after the above-mentioned continuous annealing treatment is almost unchanged from that before the treatment, and has wavy irregularities in the width direction and longitudinal direction. It is about ±1ms for Habo2Ryu. Furthermore, since uneven cooling of the copper strip is alleviated, the uniformity of the material of the copper strip is also improved compared to the conventional method.

As described above, according to the present invention, it is possible to cool the strip to a desired temperature at a uniform cooling rate in both the width direction and the longitudinal direction, thereby eliminating uneven contact between the copper strip and the cooling roll as in the conventional method. There is no deformation of the copper strip or uneven temperature distribution due to this, and the desired uniform cooling process can be achieved. In the above explanation, continuous annealing treatment of steel strip was taken as an example.
Cooling treatment of coated steel strip in continuous hot-dip galvanizing line,
It is also useful for cooling treatment of metal strips in lines that involve heating and cooling of various other metal strips. .

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of the cooling device of the present invention, FIG. 2 is a diagram illustrating the contact portion between the cooling roll and the copper strip in the device of the present invention, indicated by arrows nn, and FIG. 3 is a schematic explanatory diagram of the cooling device of the present invention. A schematic explanatory diagram of an embodiment, FIG. 4 is a schematic diagram showing an example in which the cooling device of the present invention is applied to a continuous sintering equipment, and FIG. 5 is a schematic diagram of a conventional cooling device.
FIG. 6 is an explanatory diagram of a contact portion between a cooling roll and a copper strip in a conventional cooling device. l, 2: cooling roll, I-1, 2・1・refrigerant flow path, W:
rope belt. Agent Patent Attorney Arata Miyazaki Department Figure 1 Figure 3 WJ Figure 4 Figure 5

Claims (1)

[Claims] (11) In a cooling device that cools a metal band by winding it around the body circumference of a cooling roll through which a cooling medium is passed and transferring the metal band, the metal band is placed on the back side of the metal band opposite to the cooling roll. A metal strip cooling device characterized in that one or more than one cooling roll is provided in contact with the cooling roll.